The aim of this quarter-time, one-year research program is to complete three biometric studies of human mortality. First, is to incorporate the Weibull distribution into RATE, a widely used computer program designed for the analysis of event histories, and then to apply this extended apparatus in a multivariate analysis of the infant death experience of the 1975 United States birth cohort. Second is an analytic study of the multi-person survival of idealized graduation cohorts. New algebra and associated computer programs will be developed for this purpose. Third is to modify several standard techniques pertaining to cause of death analysis and estimation of years of life gained by cause deletion in such manner as to permit their application to the study of married couples and then to apply this methodology to recent United States experience. In all three projects statistical or probability models are employed.